FUNCTION: [Summary is not available for the mouse gene. This summary is for the human ortholog.] This gene encodes a subunit of the Integrator complex. This protein complex binds the C-terminal domain of RNA polymerase II and likely plays a role in small nuclear RNA processing. The encoded protein has similarities to the subunits of the cleavage and polyadenylation specificity factor complex. Alternatively spliced transcript variants have been described.[provided by RefSeq, Feb 2010]